Snubber circuits are routinely used to reduce the dV/dt across switching networks and to reduce ringing. This is usually done with series RC networks placed in parallel with the switch as shown in FIG. 1. There an electronic switch 10 is in series with a source impedance 12 and a load impedance 14 across a voltage input Vo to ground. A snubber network, including a resistance R 16 in series with a capacitor C 18, is in parallel with the switch 10. This circuitry costs energy due to the joule heating of the snubber network. At cryogenic temperatures this can lead to large losses amplified by the refrigeration factor. For example for LN2 systems (liquid nitrogen) the refrigeration factor can approach 12 watts refrigeration per watt of dissipation at 77K.
High performance cryogenic solid-state switches such as MOSFETs operated at low temperatures exhibit extremely high switching speeds, and are therefore prone to ringing. One can reduce the ringing by slowing down the gate voltage drive at the cost of higher energy dissipation. One can also add snubber networks, which produce additional dissipation. In many devices, such as thyristors, one has no alternative but to add snubbers. In some cases, the switches (particularly thyristor-based devices) are very sensitive to false triggering due to high dV/dt and require snubbers to operate.